The short and puzzling political career of Mark I. Frank came to an end today, leaving in its wake a confused Maryland General Assembly and a still underrepresented district in northwest Baltimore.

Frank, politically unknown 27-year-old auditor for the Maryland civil defense agency, was appointed Saturday night by Gov. Marvin Mandel to fill a vacancy in the house of Delegates created by the death in December of former Del. Murray Abramson, a Baltimore Democrat.

Today, in a short letter to Mandel, Frank declined the appointment he had accepted only two days ago, citing the cold spell-induced pressures of his job as the reason he cannot serve in the House.

It was a peculiar turnabout for Frank. According to Mandel aides, Frank came to the governor's attention only because he called Maurice Wyatt, Mandel's patronage man, entirely on his own initiative to ask to be considered for the seat Abrahamson vacated.

Frank's abrupt change of mind is by no means the only peculiar circumstance that surrounds the choose of someone to fill Abramson's seat. Frank is the second man nominated to fill the vacancy; his failure, and the equally bizarre failure of the first candidate, have combined to create a situation in which no one knows who now is supposed to try picking a successor to Abramson.

The first person tapped for the seat was 22-year-old James Dorf, son of a Baltimore Supreme Bench Judge, and grandson of 78-year-old James H. (Jack) Pollack, Baltimore's longest-reigning political boss.

Dorf was chosen not by Mandel, but by the politically-divided Democratic Central Committee for his district, which is the heavily Jewish inner-city area Mandel represented for 25 years in the legislature.

State Sen. Rosalie S. Abrams, one member of the central committee, voted for Abramson's widow, Helaine, to take her husband's seat. Morris Alperstein, a Pollack supporter who is on the central committee, voted for Dorf.

The deciding vote was cast by Dorf's sister, Jayme, the third member of the central committee, but the Court of Appeals ruled on Friday that Ms. Dorf is not eligible to be on the central committee, because she has moved out of the city to live in Baltimore County.

The court's ruling threw the choice of Abramson's successor to Mandel. With Frank's rejection of the opportunity to serve, there is now some question about who next gets to choose someone.

"What it boils down to is whether what we have now is a continuation of the original vacancy, or are we now looking at the Frank vacancy?" said Deputy Attorney General George Nilson."Was there enough done relative to naming Frank to the seat to create a new vacancy?"

If enough was done relative to Frank's appointment that he was technically a delegate for a day, and then resigned, Mandel may not have the power to appoint his successor, Nilson said. If the vacancy still technically is Abramson's, he said, the appointment is Mandel's.

But what if the appointment is not Mandel's? With Ms. Dorf's ineligiblity, there are now only two members of the central committee, each too closely wed to warring political factions to be able to agree on a third member.

If they cannot agree on a third committee member, the choice goes to the chairman of the state Democratic Party. The chairman of the state Democratic Party is Sen. Roy N. Staten, the Senate majority leader and one of Mandel's most loyal allies in the legislature.